Known metering devices require between 20 and 100 microliters of sample liquid in order that a volumetrically determined sample quantity of 1 microliter can be metered into the injector. Unfortunately, sample quantities of this order of magnitude are often not available, for example when physiological fluids, which occur in quantities of 1 to 2 microliters, are under investigation. Accordingly, there is the problem of metering a quantity sufficient for analysis even when the sample quantities are very small, on the order of 1 microliter. Because of small sample sizes dead or unused volumes in the transfer line between the sample vessel and the injector are to be avoided.